This invention primarily relates to external pressure resisting shell structures, although its inherent structural rigidity can extend its usefulness to many other kinds of loadings such as internal pressure, gravity and wind loads, and concentrated forces. In the past, various geometrical shapes have been ued in the construction of such shell structures, including spheres, cylinders, toroids, paraboloids, ellipsoids, and combinations of these shapes. These shapes exhibit difficulties or disadvantages however. Because special forming operations such as machining, forging, spinning, rolling, casting, etc. are required to introduce the required curvature to these elements, these shapes are expensive to fabricate. Also, fabrication tolerances on such items as circularity or sphericity must necessarily be kept small in order to preserve buckling resistance and to minimize stresses occurring in the shell wall, again making these structures expensive to fabricate. Also, the inherent restriction of the above-mentioned techniques necessary for formation place a limitation on the size of the structural components from which a designer can select. The above-mentioned disadvantages limit the practicability of manufacturing large dimension (diameter, span, length) shell structures.